Another case of vibration on 01 pete

Cupping is usually caused by bad shocks....

 

Check your RIDE Height and also check your Drive line angles also look for possible out of phase U joint.

 

Ditto the above, and take a look at the hanger bearing too.
Whenever mine went out, it did about $4k damage. Heck of a price to pay for ignoring a little vibration!

 

I'll try to help, cause I love working with problems like this. Yeah, I know...I need to get a life. I'll try to tie in the cupping with the vibration as I do believe they are related, but we first need to separate each into their own cause and effect.

The posts above offer some good advice, especially regarding the shocks. However, in my experience tire cupping on the steering axle commonly comes from 1)inflation, 2)tire balance, 3)tire mismount, 4)a bent rim, 5)loose wheel bearings, or 6)tire feathering (i'll get to this in a bit). The first five are all easy checks. I would likely rule out the first two as it sounds that you've been through those. However, if you haven't done so already, jack up the front end and rotate the wheel checking for tire mismount (make sure the mold rings are evenly spaced around the wheel rim) and a possible bent wheel or hub (aluminum hubs are especially prone to deformation from curb strikes). Place an object close to the wheel and rotate the wheel assembly looking for a wobble (up, down, in, or out). You won't need any fancy tools except for a jack to do any of this, and just a slight wobble will cause your vibration.

If you don't find anything with the previous checks, I would assume feathering to be a cause to the cupping. Now, to explain, the same forces that cause feathering (toe in and toe out) will also cause cupping over the long term since the tire winds up "chattering" down the highway. Look for feathering wear in your steer tires...if you find such, it could be the cause of your tire cupping issues.

Now, lets address your vibration issues. It sounds, from your post, that the vibration is in your steering wheel and feet (front end), and not in the seat (rear end or driveline). I'll admit that once you have a prevalent vibration, it is pronounced and felt everywhere. But, we want to find the root cause, and that sounds as though it is in the front end.

With front end vibrations, there will generally be three types...those that start under 40mph are generally associated with tire out-of-round issues. Those that start over 60mph are generally associated with tire balance issues. Finally, those that start between 40 & 60 mph are commonly associated with toe out problems (this ties in with the feathering wear previously mentioned). Look for feathering wear on the steer tires. On the top of the tire, run you hand over the tread feeling for smoothness and roughness. If when pushing your hand inward, the tire feels smooth (and rough going out), it's classic toe in. If pulling your hand outward, the tire feels smooth (and rough going in), it's a problematic toe out condition; which, beyond what's been previously mentioned, will cause all types of handling issues including your vibration.

If there is one piece of advice to give and have someone understand, it's that you need to ignore the alignment numbers you were given, and read the tires. Alignments are performed in a "relaxed" position, not representing the vehicle under load or service conditions. I don't want to say that they are totally worthless, you just need to understand that there are limitations to their "magic".

Try the above and let us know what you find. It is not uncommon to find toe out on one steer tire with toe in on the other...I'll address that if you find such. BTW, when you put new steer tires on the truck, was the vibration noticed immediately, or did it develop over time?

Good luck, and I hope this helps!

 

You must be the Wharton Tire Guru ......LOL!
Good Info!

 

I'd check the ride height first. Call pete with the vin and they will tell you the bag height that number you average out over the four bags or between the front and rear on each side.
Being a werner truck my second thought would also be out of phase driveshaft. All it takes is for one of them rookies to dump the clutch one time to slightly tweak the driveshaft and the u joints are no longer perfectly in line. I had a truck like this once and it sounds allot like what you are experiencing

 

Just a couple of thoughts, your problem sounds a little different than mine was, but please don't assume that because you replaced a part, it's now OK. My hanger bearing turned loose 102 days after the purchase, (90 day warranty, of course).

Depending on how many miles you run, and the severity of the steer tire cupping, that may, or may not be a bad thing.

Three axle alignment?
Check to see if you lost any balance weights off the drive shaft?
Don't know about Petes, but KWs will get play in the sliding steer shaft between the steer box, and the firewall.

 

Check for out of round brake drum,or the wrong drum.Might also check crankshaft damper(some call it a balancer).
Good info.,AgLaw. Thanks!

 

Yes... Thanks rjones! You would also do well to check that the drum is properly piloted to the hub. Much like wheel piloting, the drums are also piloted, and if the wheel/drum assembly is tightened off kilter, it'll present some similar symptoms. I've seen some hubs (again, especially the aluminum ones) where the drum pilots have been damaged by some renegade mechanic not following proper mounting techniques, and the brake drum will wind up being off center/out of round. The only real solution is a new hub. However, you would normally notice some pulsating/pulling from the bad assembly.